Frequency diversity is a well known technique in the prior art that can be used for better channel adaptation and also for interference mitigation means. For example, in the next cellular standard after LTE, the LTE-Advanced, several carriers are used simultaneously for frequency diversity and also to achieve higher throughputs.
Frequency diversity is a known method for don't-put-all-your-eggs-in-one-basket motivated communications, since any individual fixed frequency may be plagued by noise, interference and so forth. Some protocols provide a certain level of frequency diversity which may or may not be sufficient for particular applications while others provide none.
Many communication systems typically use a fixed center frequency. For example, some wireless cellular communication systems such as 2G (CDMA) 3G (WCDMA) and 4G (WiMax, LTE) uses typically fixed center frequency for the communications within the cell. Sometimes all the cellular networks can be operated using a single fixed center frequency (in case of frequency reuse=1).
It is known that as a communication system moves from one center frequency to another, there is a transient time period which is prone to error, typically both at the transmitter end and at the receiver end, due to the “settling time” required by the hardware to adjust to the new frequency.
A variety of frequency converters are prevalent in the art.
Layer 1, 2 and 3 relays are known.
Many different communication protocols such as LTE, 3G UMTS, WiMAX, WiFi, OFDMA, CDMA and TDMA are known.
Receivers which recognize elements of a known protocol, such as cyclic prefixes, are known.
The disclosures of all publications and patent documents mentioned in the specification, and of the publications and patent documents cited therein directly or indirectly, and of specifications of mentioned protocols are hereby incorporated by reference.